Size-reducing apparatus



R. s, BUTLER 2,168,084

SI ZE-REDUC ING APPARATUS Filed Dec. 3l, 1934 5 Sheets-Sheet 1 IT. 4 r

Aug. 1, 1939.

R. s. BUTLER 2,168,084 A SIZE-aanname APPARATUS Filed Dec. l51, 1934 v5 Sheets-Sheet 2 Aug. 1, 1939.A R. s. BUTLER 2.168.084

sIzE-n'EDUcING APPARATUS File Dec. 31, 1954 5 Sheets-Sheet 3 Hoerillg'tier BY I ,I i

ATTORNEY.

R. As. BUTLER 2,168,084

SIZE-REDUCING APPARATUS Filed Dec. 51, 1934 5 Sheets-Sheet" '4 INVENTOR.

H030; cier BY Aw. M Ilm/pm,

y rmRNEx llgl, 1939- v I R. s. BUTLER 2.168,084

S I ZE-REDUC ING APPARATUS Filed Dec. 3l, 1934 5 Sheets-Sheet 5 In uen Zo r Ro eriuler.

bfi/M MMM/m'. airy Patented Aug. 1, 1939 PATENT OFFICE I 2,168,084 size-REDUCING APPARATUS Robert S. Butler, Claremont, N. H., assignor to Sullivan Machinery C Massachusetts y Application December 3 18 Claims.

My invention relates to material-size-reducing mills, and more particularly to apparatus for reducing material of moderate initial size to the ,nest commercially desirable sizes, although in 5 its broader aspects no limitation as to materialsize is to be inferred/ I Fine-grinding is a process of increasing y'commercial importance, and is becoming still more important with the growing use of pulverized l0 fuels. It is accordingly of great importance to provide, for the operation of fine-grinding, as well as forother size-reducing operations, apparatus which will function as efficiently as possible.v Among the factors which contribute to efficiency are: abundant discharge area-for adequately reduced material; the avoidance of choking of the apparatus; controlled'and regulated feed of material to be processed, to the apparatus; the classification of the size-reducing media and the 2o material to be reduced, so that coarser particles of material shall beacted upon by the coarser size-reducing media andner particles of ma terial by the smaller size-reducing-medium elements; intense activity of the material and the Size-reducingKmedia so as to eifect a maximum processing rate; the prevention vof short-circuiting of the material within the mill, with resultant over-size reduction of part of the material;

and assuring that the size-reducingmedium shall work upon'the material to ljbe reduced in size and not upon itself. The capacity to reduce the power consumption as the processing rate is reduced, is also of great desirability.

y lIt is elementary that choking of a mill can be certainly avoided only when the rate of feed does not exceed the rate of size-reductionfand Y discharge of the material to be processed. It is also elementary that inadequate feed rate means A loss of-.output. A truly self-regulated feed is 4o therefore of great importance, but heretofore has not been found practicable, so far as I am advised, as the secret of taking care of the variables, such as sudden differences in the processability of the material to be reduced in size, variations due to voltage changes, for example, in

the drive of 'the' mill, differences in moisture content of the material fed, etc., has not previously been discovered. In large mills, such as ball mills, where there is a great deal of spare space fluctuations of the type mentioned could be cared for, but the general inelciency of -the apparatus as a whole and lits relatively enormous size and ex- 4 pense, make a simpler arrangement very important. If it is possible to provide a self-regulating feed ompany, a corporation of 1, 1934, Serial No. 759,902

(ci. ss-s) in which .conditions within the chamber itself control the rate'of admission of the material to be reduced, it is obvious that the necessary control can be secured; and it is an object ofv my invention to provide for this result, and the apparatus herein described will accomplish it. 1

Rapidity of discharge of the fully processed material is obviously of great importance, as material which is adequately reduced in size should be gotten out of the mill to make -place for new material. Maximum discharge can be obtained by the provision of a rather shallow, wide cham ber, and, .as will-later be apparent, great activity of the materialvin process contributes to rapidity 1: of discharge; and my invention has for one of its objects the provision of improved means for effecting maximumdischarge rate, and will be found to provide for very rapid escape of the fully processed material.

'I'he classification of material and size-reducing media (meaning by the latter, balls of various sizes, or other shapes of material of sufficient hardness to be used in the Size-reducing operation) according to size, is important, for when large particles of material can be subjected to the action of the larger and heavier reducing elements andthe partially reduced material may be subjected to the actionof the smaller reducing elements, it will be found that more useful blows per unit of time will be struck and the blows will be better adapted to the work. Furthermore, the attrition effect will be a maximum in a classifledarrangement of material and reducing units as described. Such .a classificationl of the material and of the reducing media will'be found to occur to a maximum degree where centrifugal action takes place, for the denser material, that is, the material of small unit size, will move as far as possible from the axis of oscillition due to its greater density, when the action and circumstances are such as will permit this arrangement and rearrangement, and thereby size-reduction will be effected with maximum eiiiciency.

Another feature of very great advantage will be found to lie in the employmentof an oscillatingI chamber, provided, of course, that chamber be arranged so as positively to impart to the contents thereof arcuate movement, due to the tendencyl of the chamber contents to travel at all times at a tangent to the-direction of chamber oscillation; ani-l. with an arcuate chamber l form it will be found that accordingly there is heavy pressure, particularly with substantial quantities of ma-v terial 4and reducing media and considerable4 weights thereof, of material on the bottom of mentally so that the load therein, that is, .the

mixture of size-reducing medium and material to be ground, maybe treated as a coherent mass. In eiect, the contents may be thought of satisfactorily as a plastic piston of mingled media, of changing compactness and density at different points in the processing chamber cycle of movement. The chamber dimensions with referencey to length are desirably limited so that the free play, so to speak, of the material contained therein will not exceed a certain value. When the chamber is receiving no material to be reduced and contains reducing vmedium only, if such quantity does not exceed the desired maximum it will/be found, that the reducing medium will not absorb more energy than that due to fric.- tion between it and the floor and walls of the chamber. When material to be reduced is added at the proper'rate and the quantity of mixed material within the chamberincre'ases so that the free play again attains the proper value, it will be found that maximum reducing eiciency will be attained, although substantial variation from this figure will not result in greatly reduced efiiciency.

determined in such a manner that the piston-like action may be attained. Obviously, the actual height will depend in great measure on the quantity of material contained in any given chamber,-

oscillation of the chamber; internal classication .x of medium and material is possible, and centrifugal force may be used to a maximum degree. An arcuate chamber form is desirable because of the uniformity of action, its efficient cooperationin .control of feed, the increased attrition which results from the tangential tendency of movement of the material to be processed and of the reducing medium, the reduction in power necessary to operate the mill through return of energy to the driving apparatus because the tangential pressure of the load moving along the arcuate bottom of the chamber tends to resist deceleration of the moving system, etc. Feed should be regulated to avoid choking, and is best controlled from within the mill. Discharge area should be 05 a maximum. The load should be adapted to the design of the mill and maintained not in excess of the efcient maximum. Obviously, lightness is an important feature. Single or plural chambers may be used, with staging if desired.

The foregoing statements as to preferable characteristics are not to be understood to exclude as embodiments of my invention mills lacking certain of ,the enumerated features, and all rights 'th-respect to all constructions falling within he scope of theappended claims and/or em- 'the processing chamber 'in its path.

, tioned. The vertical height of the chamber should vbe bodying any of the aspects of my inventionv herein described, are expressly'reserved.

For the purpose of establishing a vocabulary, for the readier discussion of the invention, it may be said that the terms medium and 5 media will be used from time to time to designate the freely moving reducing means contained within the processing ,chamben Such media may consist of chrome or other alloy steel balls of various sizes, steel shapes other than 10 sphierical,l and particles, so to speak, of various sizes If material having hardness` appropriate to the reducing action required. Stroke will be -employed to designate the range of movement. o1'

meansthe free travel of the concentrated load between its v-position when concentrated in one 4 end of the processing chamber andthe other end of the latter. As will later be more fully pointed'` out, play from 1;5 to 1.75 times the stroke is a 20 very desirable value, but when less .sharp impact is required, smaller play is very satisfactory, and higher values are not prohibited. Load will, be used to designate the combined mass of reducing medium and material to be reduced in size. 25 Loads less than fty percent of chamber volume are relatively undesirable; and a load of approximately sixty-sixpercentof the chamber volume will provide very ei'ective reducing operation. Reduction willv be used as a general designation fi for the various operations of crushing, pulverizing, etc., and in the form of reduction or reducing will be generally used to cover all of the various types of. operations just individually men- With a properly designed chamber, the load will act as a valve. If a' load decreases below the maximum desired, due to a decrease in feed rate, power consumption will decrease, the rate of decrease being governed by the rate of decrease 4 in load, that is, the rate of discharge. lWhen the load consistssolely of reducing media, the play with a properly designed chamber will increase derive from the chamber, other than from fric- 1 tion upon the chamber walls, any tendency toward movement, and therefore thepowe' consumption will be only that requisite to overcome the friction of the., moving parts of the apparatus. Whenfeed again commences, the load will increase,the play will shorten, and the load activity will increase until the load has reached its maximum point of efliciency, where it will l. remain due to the proportioning of the chamber and supply passage design. l1 From one aspect, my invention comprises a chambered mill element, a relatively movable chamber-enclosed reducing medium associated therewith, and means for effecting relative move' ment between the chambered element and the associated mediumv involving reversals of movement. Preferably, rapid oscillatory movement will be provided, and, very desirably, pivotal movement of the chambered element will be selected. Arcuate chamber form and graduated size of the relatively movable reducing media are very advantageous. While, obviously, different pivot locations may be selected for the chambered element, a pivot location near the point of initial material ingress facilitates feed; and a top pivot 70 improves smoothness ofyoperation, makes easier the discharge of processed material and promotes attrition. Arcuate chamber form in conjunction with pivotal chamber movement increases size reduction by attrition and conserves power.l The 7 6 with-my invention', and all the features disclosed.

in the discussion of preferred constructions are within thecntemplation of my invention fromits several aspects. y

object of my invention is to provide an improved size-reducing unit. Another object of my invention is to provideV an improved apparatus for the purposes stated which will be relatively light, require relatively little power, and yet develop powerful forces. A further object of my invention is to provide an apparatus of the character specied in which quite high velocities of the reducing media/maybe obtained and in which through reversals of direction a much greater impact eect and reducing activity of the reducingl media may be obtained when desired, and a reducing action adapted to the material to be reduced secured.A Still another'object of my invention is to provide an improved apparatus of the type specified` in which maintenance ex- .pense will be reduced to a minimum. Yet anotherobject of my invention is to provide an improved apparatus of the type specified in which auto- "matic feed Without. interruptions in the operation of the device may be effected, and in which the rate of feed will be automatically controlled so as to prevent choking and to maintain a high degree of efficiency of reducing operation. Still another object of my invention is to provide an improved apparatus of the type mentioned 'in which attrition, as well as impact, may be availed of in very large measure. Yet another object of my invention is to provide an improved appa` ratus of the type described in which the flneness of the product may be readily automatically controlled, and products insufficiently reduced may be returned to the action of themill. Still another objeet of my invention is to provide an improved reducing apparatus, in which, by mechanism inherent in the apparatus itself, a variation in the ilneness of the end product may be readily effected. Still another object of my invention is'to provide Van improved mill in which an improved movement of the parts cooperating in the reducing action is incorporated, whereby,

with a device lighter by far than any present commercial installation, a higher output per unit of weight, per unit of space, per unit of power, and` per unit of time, may be' obtained. Yet another object of my invention is to provide an improved mill in which the power consumption will be greatly reduced as the feed rate diminishes or.

duction of the material to be reduced, in a manner never previously attained. Still vanother object of my invention is to provide an improved oscillatory type mill having provision for effecting continuous feed and discharge. Still another object of my invention is to provide an improved rocker type mill having improved dischargel means whereby discharge is ,eiected, at least in part, in a direction opposite to the normal action of centrifugal force on,y the material being reduced. Still another object of my invention is to provide an improved rocker type mill in which a very wide range'of variation in the charge of.

size-reducing elements shall be possible without seriously impalring the eiliciency ofthe apparatus vor changing the quality of the product, whereby I even negligent attention to the operation of the mill will not be able to result in an unusable product or a gross waste of power. Still another object of the invention is to provide a mill having provision whereby during extended periods of reduced demand for its product the mode of operation thereof may be altered'to diminish the required power input while still providing an d adequate but reduced quantity of end product of the same qualities as is produced when the mill is being operated at maximum capacity. *Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawings, in which, for purposes of illustration, two illustrative embodiments of the invention are shown,

Fig. 1 is a side elevation, with parts broken away, showing a preferred illustrative'form of my invention incorporated in the form of an impro'. ed coal pulverizer.

Fig. 2 is an end view from the right of Fig. 1, with parts broken away.

Fig. 3 is a plan view, with parts broken away.

Fig. 4 is a section on a plane corresponding to the line 4 1 of Fig. 1.

Fig. 5 is a section on a plane corresponding to the line 5 5 of Fig. 2, the section', as will be noted, extending longitudinally through the machine.

Fig. 6' is a vertical section on a plane corresponding to the vertical line 6--6 of Fig. 5.

Fig. 7' is a vertical'section showing the pulverizing chamber oscillating mechanism, the section being taken on the plane corresponding to the line l-Lof Fig. 6. v

Fig: 3' is a 'fragmentary view of a portion of the end .of the-pulveriaing chamber.

Fig."9 is a side elevation, with parts broken away, showing another illustrative form of my invention embodied in a somewhat different improved coal pulverizer. f.

Fig. 10 is an end view from the right of Fig. 9, with parts broken away.

Fig. l1 is a plan view, with parts broken Fig. 12 is va section on a plane corresponding to the line |2-l2 of Fig. 10, the section, as will be noted, extending longitudinally through the ma. chimes- Fig. 13 is a vertical section on a plane corresponding to the vertical. line IB-I of Fig. 12, the section cutting through the oscillating pulverizing chamber.`

Fig. 14 isa .vertical section showing the pulverizing chamber oscillating mechanism, the section being taken dn a plane corresponding to the liney ltu of Fig. 13.

Fig 15. ifs'a vertical transverse section on a plane corresponding to the. line. I5-|5 of Fig. 9, showing a portion of the driving mechanism aWay.

for the plverizing chamber oscillating mechanism.

Fig. 16 is a section on the intersectingplanes corresponding to the line I6-I6 of Fig. 12.

Figs. 17 to 20 inclusive arediagrammatic views showing different relative positions of the pulverizing chamber and its contents.

Referring rst to Figs. 1 to 8, inclusive, of the drawings, it will be observed that in the illustra.- I

tive embodiment of the invention therein disclosed, a frame, generally designated I and which comprises a base portion 2 and three upright walls 3, 4 and 5, is provided. The walls 4 and 5 are connected by end wall portions 6 and 1 to form a chamber 8 in which the driving apparatus isenclosed in part. The walls 3 and 4 are connected by top, transversely extending members 9 and I0 which rigidly space the walls 3 and 4, and these walls are further connected by a hollow tubular member II which provides a housing for a transversely extending crank shaft I2, which is journaled`within suitable sleeve bearings I2'. The member II is provided with a lateral portion I3, which has a hand-hole cover I3' thereon so that access may be had to the space within the member II to permit the removal or replacement of 'the bearings I2' when desired.

Suitable chambers I4 surround the bearings and are adapted to be supplied with lubricant through openings I5, while the outer bearing I2\is sealed by a felt gasket or washer I6 suitably held in position, as by a covr I1. The crank shaft I2 has a drivingpulley I8 to which power may be supplied through suitable driving connections, as for example by a belt I9 driven from any suitable moytor, not shown; and this shaft serves to rotate a crank disc 20, from which a,drive pin 2| projects .eccentrically. The pi 2I is connected by a connecting rod 22 with a pin 23, which may be positioned in the desired one of the openings 24 in a depending arm structure 25, which at its upper end is flxedly connected to Aa transverse hollow shaft 26. Upon the vhollow transverse shaft 26, which is suitably supported in bearings 21 and 28 carried by the frame members 3 and 4, there is supported a size-reducing or pulverizing chamber member generally designated V29. The hollow shaft 26 at one end thereofthe end opposite the point of connection4 of the arm structure 25-communicates freely with the interior of a supply'chute 30, and the lower wall of the hollow shaft member 26 is cut away as at 3l to provide an opening, through a gradually expanding radial feed passage 32, into the interior space 33 of the pulverizing chamber member 29. The pulverizing chamber member 29 may be built in any suitable manner-whether of plates suitably cut,

hollow shaft member 26, a bent plate member 36 which forms the bottom, ends and lateral top'portions of the chamber, which plate is welded to the members 35, and a pair of end plates 31 and 38 welded or held, as by machine screws or the4 like, to the most widely spaced and heavier ones of the elements 35 and 36. For the-purpose of providing for discharge of adequately pulverized material, numerous arrangements and provisions may be made. In this form of my invention I have shown provision for a very large discharge area, and it will be observed that the plate 36 substantially throughout its length, and also the side plates 31 and 3B, are provided with dischargeorifices or slots, so that top, bottom, end and side escape of the pulverized material may be made possible..` The discharge orifices in the plate 36 are designated 36 and those in the plates 31 and 38 are designated 31' and 38'.

Appropriate liners, conformed to the shape of the inner walls of the pulverizing chamber and made of chrome-alloy steel or other material having the necessary wearing qualities, or, if steelis detrimental to the process, other suitable material, may be provided, but as such construction will be obvious to those skilledl in theart, the drawings are not complicated by the showing of this additional feature,

The 4size-reducing pulverizing chamber will be noted to move arcuately about the axis of the hollow shaft 26 between the side walls 3 and 4, and a suitable relatively light, arcuate pan or bottom enclosure member 39 is bolted or clamped as at 40 to the opposite side members 3 and 4 and provides, as it were, a bottom and end walls for a rocker chamber 4I. The top transverse members 9 and I0 support an upright, upwardlytapering discharge chamber cover 44 which supports at Vits top 'apparatus for maintaining a pressure differential between the space within the reducing chamber proper and the space surrounding the latter. The construction may o bviously vary, but for purposes of illustration there is shown a discharge connection 45 supported on the top of the'mcmber 44 and at its upper end supporting a further discharge connection 46 whose interior communicates with a discharge line 41 in which a draft of appropriate intensity is produced by suitable means, as for example, a blower or air jet device 43. L. Itis to be understood,

of course, that the blower device shown is merely illustrative of means for placing the interior of the chamber surrounding the reducing chamber under-an appropriate suction, and any other suitable means, such as a fan, a properly screened suction pump, or the like, could be used instead of the apparatus shown. The interior of the discharge connection' 45 is divided into a plurality of parallel upright discharge connections 56, 5I, 52, 53 by vertical parallel septa 54; and dampers 55 suitably manually or otherwise controlled are provided, herein at the base of the vertical discharge connections, to enable appropriate draft modulation. The several discharge passages extend upwardly, stillV separated from each other by septa 56 formed in the discharge chamber 46, nearly into alinement'with the bore of the discharge connection 41 extended rearwardlly.

Within the interior 33 of the reducing chamber member 29 there is enclosed an appropriate free reducing medium, herein in the form of a charge of balls, shown at 51, which may occupy, depending on conditions, say, from twenty to sixty percent by volume, of the interior of the chamber 33. These balls may vary in size from somewhere around an inch in diameter down to a size just too large to pass through the grid openings 36', 31', 36'. The member 29 is provided with a suitably covered lateral opening 53, and the frame member 3 has a suitably covered lateral opening 59.

It will be appreciated that the reducing (pulverizing) forces generated within the size-reducing Vspace 33- will Vdepend upon the velocity of the chamber, and the masses of the relatively moving parts, and the times of .coaction between these parts. The velocity of the chamber will determine the velocity of\the contained size-reducing medium and the intermngled charge of material to be pulverized. The chamber velocity will be determined by the R. -P. M. of -the crank shaft, the throw of the crank shaft, Vand the nature of the connection' with the pendulum. Essentially, the force of the blow as affected by the mass of the moving parts, will be controllediby the mass of the moving chamber contents, for the direct power drive of the chamber will always cause the latter to have an equivalent mass greater than that of the free body within the chamber. The time of coaction between the chamber walls and the chamber contents will affect the nature of the coaction and, in a measure, the force of the coaction, for. if chamber and contents meet each other at the instant when each is traveling at maximum velocity but in mutually opposite direction with respect to the other, a very high degree of sharp impact and maximum value due to the kinetic energy of the parts will be obtained. Obviously, anything from this condition down to a condition wherecoaction between .the

freely moving chamber contents and'chamber wall takes place substantiallyat the so-to-speak dead center positions, is a possibility; and the designer of the individual machine will bear in mind the characteristics of the material to be reduced in size, in selecting values. The net free pla'y of the chamber contents (load), with the device illustrated, may be 'approximately thirty-three or thirty-four percent of chamberv length, running somewhat lower than the difference between unity and ratio of the length at one side of the opening 32 plus the width of. that opening to the whole chamber length, dueto the fact that the chamber contents will -not act like a piston of uniform cross section but will instead progressively flll to its full vertical dimension the chamber from points adjacent the end of the chamber back towards its center, as the material surges within the chamber, and accordingly material will flow down the sloping surfaces of the chamber contents in excess of the quantity which would enter were the rear edge of the chamber contents always truly radial. It is important that the chamber contents shall fill the chamber from top to bottom at each end of their travel within the chamber, and it will be noted that as the chamber is oscillated there will be a classification of material and of size-reducing medium in accordance with relative density, the larger material particles and size-reducing elements being nearer the axis of oscillation and the finer material fragments and-finer size-reducing medium occupying positions adjacent the bottom wall of the chamber, with the result thatl as the material is reduced to the desired neness it automatically approaches the discharge \area; and, moreover, large size-reducing elements :ict on large particles, and small size-reducing media act on ner particles, and thereby the impact is adapted to the work and the blows are delivered where they will -do the most good.

With this discussion of the general structural features and phenomena which characterize the illustrative embodiment of the invention which has been described, the mode of operation may be set forth in further detail. It will be evident that, depending upon the proportion of the parts, size of the'bal1s,.the weight of the ball charge,

the velocity of the pendulum, and the number of oscillations the same goes through per unit of time. and other variable factors referred to above,

the designer may provide al mill which is adapted for the size -reduction of substantially any material.- The mill so far specifically described`andi illustrated is particularly advantageous for pulverizing coal butit will be obvious that its utility V maybe maintained through the machine. oal

to be pulverized will be fed in a suitable preconditioned'fcrm to the hopper or chute 30, and will pass at a more or less uniform rate inwardly through the left-hand end in Fig. 2 of the shaft 26, and will then pass down through the passage 32 into the chamber 33, where it will be subjected to the size-reducing action of the medium 5l, as previously described. As the balls and coal intermingle and the mixture is rapidly thrown from end to end of the chamber 33 as the latter is caused to pass many hundreds of times per minute through an oscillatory cycle, the chamber contents will act almost as a piston as they'pass across the mouth of the passage 32, and thereby control the rate of access of coal to be pulverized into the chamber 33. Moreover, due to this piston-like action, there will be provided a continuous forcing of air entering the chamber through passage 32, outwardly throughthe orifices A36',

31', 38%, and so a highly efficient discharge of fully reduced material. The material passing through these discharge orices and` entering the chamber 4t will pass upwardly past the dampers and through the active passages 50', 5I, 52, 53, and out through the connection 4l to a suitable classification device (not shown), from which inadequately rduced material will be returned and reenter the chamber with the feed. Due to the arcuate form of the chamber and its arcuate path of movement, and the tendency of the chamber contents to travel in straight lines tangential to the arcuate path of the chamber, a very effective reduction in size of the material to be ground will be effected due to attrition, and power consumption will be minimized. In the event that the play be made approximately 1.5 times the stroke of the chamber, and with the chamber contentsas they will be maintained automatically, provided adequate feed is effected to the hollow shaft 26, a very high rate of size-reduction will be effected due to the development of the maximum usable energywithinthe chamb'er. ever, ifA the feed is reduced so that less rapid sizereduction necessarily results, it will be evident that a reduced power consumption will take place, and accordingly that the mill is capable of operation efliciently to meet various load requirements. It will be evidentA from what has been said above,

that so long as material is fed tothe hollow shaft How- Referring now to Figs. 9 to 16, inclusive, of the4 drawings and to the other illustrative embodiment therein disclosed, it will be noted that a frame 6|, which comprises a bed- 62, a lateral wall 63, another lateral wall 64 to which a housing 65 is connected, and spaced transverse portions 66,

provides a suitable support for the size-reducing mechanism. The wall portions 63 and 64 are interconnected, as by welding, with the opposite' endsof a tubular member 66', within which suitable -sleeve bearings 61, 61 are arranged, and having a lateral portion 68 provided with a handhole cover 69 so that access may be had to the interior of the member 66' to permit the removal or replacement of the bearings 61 when desired.

Suitable chambers 68 surround the bearings and are adapted to be supplied with lubricant through openings 69", while the outer bearing 61 is sealed- 'by a felt gasket or washer 10 held in position by a cover 1|. A shaft 12 having a driving pulley 13 to which power may be supplied through any suitable driving connection, as by a belt 14 driven from a suitable'source of power not shown, serves to rotate a crank disc 15, from which a pin 16 eccentrically projects. The pin 16 is connectible by a pitman or connecting rod 11 with a pin 18; which is positionable, depending upon the desired range of oscillation, in one or another of a series of mounting holes 19 or'19'. The mounting holes are arranged in a depending arm 80 which is secured at its upper end to a hollow tubular shaft 8|. The shaft 8| is journaled at its end nearer the arm member 80 in a cap-bearing 82 and at its oppositeend in a cap-bearing 83. The bearing 82 is carried by a projecting boss 84 formed on the wall 64 and extending into a chamber 85 formed between the members 64 and 65 and 4having a cover 86 suitably secured thereto. to provide a sealed chamber in which the drive mechanism, including the flywheel or crank disc 15, the lconnecting rod 11, the arm 80, andthe driven end of the shaft 8|, are disposed. A suitable handhole cover 81 'is provided in the wall member 65 being offset from the axis of oscillation by a greater distance than yany other portion of the oscillating structure (except the lower end of arm The pendulum 9| comprises a more or less cylindrical body 93 having walls 94 coaxial with the Walls of the hollow shaft member 8|, and supported by end walls 95. The peripheral wall of the member 93 is cut away at the upper portion thereof as best shown in Figs. 12, 13 and 16, to provide an approximately rectangular opening 96, the function of which will be later described. 'The lower part of the peripheral Wall 94 of the body 93 is provided with an opening 99, to which there leads the inwardly tapering or 2,168,084 the capacity of any. designer of ordinary skill; the

wedge-shaped passage |00-'having walls |0| ex- 'tending from the peripheralwall of the hollow lshaft member 8| to the peripheral wall at its lowermost portion of the member 93. A passage rectangular in outline and designated |04 connects the interior of the shaft 8|'with the wedgeshaped passage I 00. The discharge end |05 of the passage|04 opens into the interior |06 of a pendant chamber-forming body |01, which is secured as at |08 in any suitable manner to the lowermost part of the member 93. walls of the member 93 at opposite sides of the passage |00 are provided with a series of long, narrow, circumferentially-extending slots H0, which may desirably be somewhat less than 1A," in Width for the particular size and type of sizereducing apparatus which constitutes the illustrative embodiment. 'I'hese slots, of course, it will be noted, connect the space within the member 93 and the chamber |06. The chamber |06 is herein approximately a quadrant in angular extent and has a lower imperforate wall ||2 struck on an arc from the center of the axis of oscillation of the shaft 8|. It has end walls ||3 which lie in planes extending radially from the axis of oscillation of the hollow shaft 8|.- These walls may.

also advantageously lie in planes which intersect in a line below the axis of oscillation is desired. The ends ||3 and bottom Wall ||2 are reinforced by flanges or webs ||4. The chamber may be suitably lined with replaceable liners i f desired, as for example, by liners of chrome or other suitable alloy steel or any other suitable material--a rubber liner being desirable under'some conditions; but as the construction of such ele- 1 ments is well known to vthose who are skilled in the size-reducing art, they will not be described or depicted. A suitable elbow connection I6 is mounted on the frame member 63, having a mouth extending into the interior of the hollow shaft 8|, and provided with a wide-mouthed chute ||1 for receiving material which is to be reduced in size, and deliverng the same, through the elbow' I6, into the interior of the shaft 8|.

'I'he lower Upon the top of the frame heretofore described, 1

and suitably heldy to the cross members' 66 thereof is an upright frame, supporting -on pedestal members ||9, ||9 a -discharge connection |20, at whose upper end there is mounted a further discharge connection member |2| whose interior communicates with a discharge line |22 in which a draft of appropriate intensity is4 produced by a blower device |23. It is to be understood that here also the blower device is merely illustrative of means for placing theinterior of the sizereducing apparatus under an appropriate suction; and any other suitable means such,as a fan, an appropriately screened suction pump, or the like, could be used instead of the apparatus shown. The pedestals ||9 support arcuate walls |25 with whose interior the peripheral surfaces of the cylindrical' wall 94 of the oscillating member 93 make a close fit. These arcuate walls 25 extend upwardly from a horizontal plane, herein shown as including the axis of the hollow shaft 8|, through an angle of somewhat more than 45, and terminate in the upright parallel end walls |26 of the discharge connection element |20. The interior of the discharge connection |20 is divided into a plurality of parallel, vertical discharge connections |21, |28, |29, |30 by vertical,

parallel septa |3I; and dampers |32 suitably,v

2,168,084 Aor more of these discharge passages to provide appropriate draft modulation. The several discharge passages extend upwardly, still separated from each other by septa |3|' formedin the discharge member |2|, nearly into alignment with the bore of the discharge connection |22 extended rearwardly. The pendulum member may advantageously. be provided with an, up-

wardly extending fan or vpaddle member |40, se.

cured thereto opposite the supply passage |00 and midway between the sides of the lateral opening 96.

'I'he fact that suction devices are shown and described for the carrying away of the dry sizereduced material does not imply that means for effecting a pressure differential by superatmospheric pressure is not within the contemplation of the invention. Indeed, any means for effecting processed material movement by means of a fluid capable of maintaining it in suspension is to be understood to be within this aspect of the invention'.

It will be noted that air may enter ,the open end of the hollow shaft 9| with the material supplied `through the chute ||1, and may pass through the passage |00 down into the pendulum chamber |06. It may pass outwardly through the opposite ends of the pendulum chamber through the grids l0, around thearcuate portions lying between the coaxial walls of the hollow shaft member 9| and the casing 93, upwardly. through the opening 96, upwardly through the discharge passages |21, |29, |29, |30, and through the discharge connection |22. Aside from the restriction provided at the opening |04, there is arranged a progressive increase in cross sectional area in the various passage portions between the point of inlet and the chamber |2|,

conditions, from twenty to sixty percent by vol-.

ume of the interior of the chamber |06. 'I'hese balls may vary in size from an inch or more iny diameter down to a size just too large to pass through the grid openings at ||0, in the particular mill illustrated and for coal pulverizing.-

The mode of operation of this apparatus will be readily understood from what has been described, but may-be summarized, with reference to coal or other material to be processed as follows. The air jet |23 is set in operation and regulated in accordance with the rate of supply and size-reduction of the coal so that a draft of from a very fewlinches of water upwards as may be desired will be maintainedthrough the machine, Coal to be processed will7 be fed in a suitably pre-conditioned (by screening) form to the hopper ||1, and will pass at a more or less uniform rate in through the left-hand end (in Fig. 13) of the shaft 9|, and pass down through the expanding passage |00 into the ball chamber |06, where it will be .subjected to the size-reducing action of the balls. As the ballsand coal intermingle 4and the mixture is rapidly thrown from end to end of the chamber |06, as the latter is caused to pass many hundreds of times a minute through an oscillatory cycle, the moving mass of reducing agent and material to be reduced in size will act almost as a piston as it passes across the mouth of the passage |00 and over the gridded discharge openings at the top wall of the casing |06, and will aid in the provision of a definite flow of air through the apparatus. The ends ||3 of the chamber |09 will direct, as they are impinged upon by the moving contents of the chamber |09, the latter downwardly. thus increasing attrition, and so cause avery effective attrition `and size-reducing action. As the materia] particles in the charge are reduced in size. the heavy balls will displace continuously upward the finely divided and' much lighter coal dust,

and as the latter reaches a suiiicient degree of,

flneness so that the same is capable of being supportcd'in the light draft of air passing through the machine, the most finely divided coal will be drawn upwardly out of the size reducing cha'mber and passaround the outside of the shaft 9| and enter the -discharge stacks |21, |29, |29, |30. The fan or paddle element |40, undergoing a motio'n similar to but opposite in phase to the chamber |06, will act upon the lrising columns of air laden with pulverized coal and deflect downwardly, as it were, striking them rearwardly, the heavier particles of dust which are tending to be raised by the air current and to pass out 0f the machine.. Because of the decreasing rate of `flow resulting from the enlargements of the successive cross sections of the passage forming meansthe're will be a reduced lifting power in the air stream, and only the most finely divided (200 mesh and smaller) particles of coal will tend to pass completely out of the riser stacks |21,- |29, |29, and enter the discharge connection |22. AThere-will be a constant reverse flow, as it were. due to the fall of the heavy particles back into the chamber |06 and upward pas- Sage of the lighter particles, and-accordingly only thepropeily conditioned, that is, reduced, coal will pass from the machine,`

For the purpose of, illustrating certain of the phenomena which occur during the operation of the mill, reference may be had to the diagrammatic showings of Figs. 17 to 20.

In Fig. 17 the mill chamber, which is shown in the form of chamber 33 merely for the purpose of illustration, contains only the charge of sizereducing media 51. 'I'he chamber is illustrated at one of its extremes of movement, and it will be Aobserved that the charge of size-reducing media does not contact' at that moment with either end ofv the chamber. The inertia of the charge is so great, and the forces imparted thereto solely by the friction thereof on bottom and sides of the chamber are so relatively small, that in the absence of the feed of material to the chamber, and indeed in the absence of substantial feedof. material to the chamber, there is no contacting of the charge or chamber contents with the .chamber ends,and therefore there is exceedingly low power consumption during the no load^operation of the mill.

Figs. 18, 19 and 20 are diagrammatic views showing the chamber and its contents in three different positions. Fig. 18 shows the chamber at one of its extreme positions of travel,- and the chamber contents in this figure comprise not only the charge of size reducing media but the normal quantity of material to be processed mingled with the size-reducing media. At the particular position of the parts shown, the `chamber contents are still moving toward the right 1I pated themselves in the right-hand end-`f the chamber, which so to speak, on right-hand dead-center? position Obviously, depending upon various factors of design, the chamberA contents may be more or less removed from their ex-` treme right-hand position, or may even, where a very low amount of impact is necessary, have substantially attainedtheir full right-hand end position, in the position of the chamberwhich is shown in Fig. -18. In Fig. L9 the chamber has reversed its travel and is now moving toward the left band has attained approximately mid-position.

The chamber contents-size-reducing media and hand end of the chamber, and a certain `amount of feedis taking place at F. through the opening 32, past the face of the compacted chamber contents. At this moment the chamber contents and the chamberpossess substantiallyidentical veloc; ities, and as the chamber commences to slow down due to thed characteristics of the driving mechanism therefor, the chamber contents move more rapidly than the chamber walls, and a condition will shortlyresult such as is shown in Fig. 20, wherev the chamber is illustrated in a position 'in which its velocity has begun to decrease, with the result that the contents are moving away from the then-rearward end of the chamber and reducing the distance between their forward face and the end of the chamber which is then in advance 'of the moving chamber-contents. In this position of the 'chamber-contents and chamber, it will be evident Ythat the feed through the opening 32 is cut off except to such an extent as may occur through the sifting of finer particles of material intq intersticesr between the larger, uppermost material fragments and sizereducing media at the top of the moving mass of chamber-contents.

It will be appreciated that there is size-reduction, taking plage between the upper surface of the chamber-contents passing beneath the mouth of the connection 32 and the lower surface of the material which fills the feed passage32.

The foregoing diagrammatic views illustrate but have not as yet contactedwithand com-v 1. In a mill, a frame, a size-reducing chamber supported by said frame for swinging movement, means including a feed passage a portion of which surrounds the axis of chamber swing for feeding material to said chamber downwardly through the top thereof at a point spaced from th ends thereof, size-reducing media in said chamber, means for swinging said chamber on its axis through a predetermined arc to effect sizereducing cooperation between said size-reducing 1 media and said chamber, said chamber having discharge orifices for size-reduced material, and means for removing material` discharged from said chamber through said orifices including means for providing for the flotation of adequately size-reduced material upwardly at the opposite sides of the feed passage portion surrounding the axis of chamberswing.

2. In a mill, a frame, av size-reducing chamber supported by saidframe for swinging movement,

means including a `feed passage a portion of which surrounds the axisl of chamber swing for 'feeding material to said chamber downwardly through the top thereof at a` point spaced from the `ends thereof, size-reducing .media in said chamber, means for swinging said chamber on its axis through a predetermined arc to effect size-reducing cooperation between said' sizereducing media and said chamber, said chamber having discharge orifices for size-reduced material, and means for removing material discharged from said chamber through said orifices including passage forming means fixed relative to'said chamber and undergoing movement with the latter for providing for the flotation of adequately size-reduced material upwardly at the v opposite sides of the feed passage portion sur- 'its middle when said chamber is in such mid-v position, means -for *oscillating said chamber clearly the no load, feed-control, classification,

and very effective size-reducing features of nur invention. y f

It may be added that between the opposite end faces of the feed connections there will also be a 'substantial amount of size-reduction of the larger pieces in the case of more friable materials, due to the impactl action between such faces andthe material moving through the feed passage.

From the foregoing description, it will be evident that I have provided 'a very eiiicient, dura-- ble, simple and economical size-reducing device, adaptable to the size-reduction of substantially any material, and one which is self-regulating as to feed and self-'limiting as to power consumption. As the advantages are fully set forth above, further detailed statement with respect thereto is not essential at this point.

While I have in this application specifically described two forms whichfmy invention may assume in practice, it will be understood that these forms are shown for purposes of illustration only, and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appendedclaims. l y

, What I claim as new and desire to secure by Letters Patent is:

rounding the axis of chamber swing.

3. In a mill, a frame, a size-reducing chamber whose ends are higher than its middle when said chamber 'is in 'mid-portion in terms of its motion, said chamber supported by said frame for swinging movement Aabout an axis located above fment with the latter and. cooperating in providing upwardly extending passages opening into said chamber and lying to the opposite sides of said material supplying passages and terminating above the top of the latter.

4.-.In a mill, a frame, a hollow shaft supported by said frame for oscillatory motion about its axis, means for oscillating said shaft 'upon its axis through a predetermined arc, a size-reducing chamber member supported below said shaft for oscillation with the latter, means connecting the interior iof said shaft with the middle of said size-reducing"chamber,V means providing a pair of discharge passages for material reduced in..

a charge ,f'of size-reducing medium in said.

chamber'.

' 5. In af'mill, a frame, a hollow shaft supported by said frame for pivotal movement, means for ,oscillating said shaft on its axis through a predetermined arc, a casing surrounding said shaft and secured thereto for movement therewith, said casing having an opening through the upper portion thereof and a plurality of other openings of which-one at least is below said shaft in the midposition of the oscillatory movement of said shaft, means connecting the interior of said shaft with said last mentioned opening, a size-reducing chamber member carried by the lower part of the casing and providing a size-reducing chamber communicating adjacent its middle with said last mentioned opening and further communicating at points spaced from its middle with the remainder of said plurality of openings, and a charge of size-reducing medium in said chamber.

6. In a mill, a frame, a hollow shaft mounted in said frame for rotary movement, a casing around said shaft and secured thereto for movement therewith, said casing being generally cylindrical and having an opening through the upper portion thereof and three openings through the lower wall thereof, means connecting the interior of said shaft with one of said openings, a sizereducing ,chamber member carried by the lower part of said casing and providing a size-reducing chamber communicating adjacent its middle with the last mentioned one of said openings. and adjacent its ends with the other two openings, and

a size-reducing medium charge in said chamber. '7.A In a mill, a frame, a hollow shaft mounted in said frame for rotary movement, a casing` around said shaft and-secured thereto for movement therewith, said casing being generally'cylindrical and having an opening through they upper portion thereof and three openings througlithe lower wall thereof, means connecting the interior of said-shaft with one of said-openings,.a sizereducing chamber member carried by the lower part of said casing and providing a size-reducing cham r communicating adjacent its middle with the last mentioned one of said openings and adjacent its ends with the other two openings, said last mentioned openings being gridded openings.

8. In a mill, a frame, a hollow shaft mounted in said frame for rotary movement, a casing around said shaft and secured thereto for movement therewith, said casing being generally cylindrical and having an opening through the upper portion thereof and three openings through the lower wall thereof,l means for feeding material to be processed into said shaft, means connecting the interior of said shaft with one of said openings, a size-reducing chamber member carried by the lower part of said casing and providing a size-reducing chamber communicating adjacent its middle with the last mentioned one of said openings and adjacent its ends with the other two openings, and a size-reducing medium 'charge in said chamber.

9. In a mill, a frame, a hollow shaft mounted in said frame for rotary movement, a casing around said shaft and secured thereto for movement therewith, said casing being generally cylindrical and having an opening through the upper portion thereof and three openings through the lower wall thereof, means for admitting air and feeding material to be processed into said shaft, means lfor placing the spacebetween said shaft and casing under suction, means connecting the interior of said `shaft with one of said openings, a size-reducing chamber member carried by the lower part of said casing and providing a sizereducing chamber communicating adjacent its middle with the last mentioned one o f said openings and adjacent its ends with the 'other two openings, and a size-reducing medium charge in' said chamber.

10. In a mill, a frame, a hollow shaft mounted in said frame for rotary movement, a casing around said shaft and secured thereto for movement therewith, said casing being generally cylindrical and having an opening through the upper portion thereof and three openings through the lower wall thereof, a paddle secured to said shaft at the upper side thereof and dividing theupper part of the interior of said casing into two chambers, means connecting the interior of said shaft with one of said openings, a size-reducing chamber member carried by the lower part of said casing and providing a size-reducing chamber communicating adjacent its middle with the last mentioned one of said openings and adjacent its ends with the other two openings, and a sizereducing medium charge in said chamber.

11. In a mill, a supporting framework, a hollow shaftjournaled'thereon, a pendulum supported by said shaft and providing an arcuately elongated size-reducing chamber, said hollow Ashaft having feeding means communicating therewith,

passage means connecting said hollow shaft with said size-reducing chamber adjacent the middle of the latter, the communication of said feeding 12. In a mill, a supporting frame, a pendulum pivotally supported on said frame for oscillating movement and having a shaft constituting means for supporting thesame during oscillation, said pendulum providing walls bounding. and defining a size-reducing chamber arcuate in the planes of oscillation of saidl pendulum anda communicating feed passage extending radially of the pendulum and opening into the size-reducing chamber between the ends of the latter, the walls bounding said feed passage being continuous and imperforate save for a lateral opening providing for the introduction, during the size-reducingoperation, of material in a1 direction transverse to the planes of oscillation of said pendulum from a point outside said planes laterally into the latter and adjacent the pivotal axis thereof, said opening lying within-said lshaft, and power means for' ranidlv oscillating said pendulum.

' 13. In a mill, a size-reducing-chamber-providing member mounted for swinging movement upon a substantially horizontal axis and providing an arcuate chamber having concentric inner and outer walls and of such extent and curvature that a straight line connecting vthe central points in the ends of said chamber falls at its middle point radially inside the central point in the curve of the inner wall of said chamber, means forsupplying material to said chamber during oscillation thereof and for discharging processed material therefrom also durin'g operation, andmeans for oscillating said member rapidly about its pivot through a path both of whose extremities lie below a horizontal plane including'said horizontal axis. 1

14. In a mill, a movably mounted size-reducing chamber supported for swinging in opposite di-4 rections about ari` axis, said chamber elongated and substantially arcuate in its planes of movement and fof a uniform width internally throughout its length and of comparatively small but uniform dimension normal to its path `of s wing, means for introducing material into feed openirig longitudinally ofsaid chamber 'and the rate and amplitude of movementof said chamber such that when said r'nill is operating at capacity during each movement'of said chamber in o ne direction along its path the same is filled completely full throughout the central zone of its length while both ends thereof are empty, whereby the chamber contents control the feed.

15. In a mill, means providing a reversely arcuately moved-chamber arcuate in its planes of movement and of substantially uniform cross sectional area on planes including the axis of movement of such chamber at substantially all points between its end portions, means for feeding material to said chamber including a feed inlet for entering material for conducting such material from a point outside said planes of movement `laterally of'the mill into such planes,-passage means communicating at one end with said feed inlet and surrounding for at least the width of the chamber the axis of movement of said chamber for conducting such material longitudinally of the axis of movement of said chamber, and a feed connection openingI into said passage means and terminating in an intake opening through a Wall of said chamber, and a charge of free size-reducing `madia in said chamber, said sizereducing media and material admitted through said feed opening forming a mass moving as a whole from end tb end of said chamber and traveling alternately back and forth across said opening while said mill is in operation and acting as a gate therefor. Y

16. In a mill, a supporting frame, a member pivotally supported on said frame for swinging movement 'and providing walls, including radially-spaced, curved, longitudinally-extending walls struck from a common axis perpendicular to the planes of swing of said member, bounding and defining a size-reducing chamber arcuate in the planes of swing of said member and of uniform cross-sectional areaon radial planes atv substantially. all points between its end portions,.

means forming a feed passage including a portion extending normally to the arc of said chamber,

and opening into said chamber between the ends of the latter and a' portion for delivering ma'- terial to said first mentioned portion, said second portion extending in a direction transverse to the planes of swing of said member and surrounding and conducting material longitudinally of the axis of swing of said member from a point outside the planes of swing of said member into such planes', and power means for rapidly oscillating said member; v

17. In a mill, an arcuate oscillatably supported chamber of an arcuate extent less than 360 and of substantially uniform cross sectional area on radial planes including the axis of chamber oscillation and cutting the chamber between its end portions, said chamber having concentric walls at its sides respectively nearest and most remote from said axis and said walls each being provided with ,discharge openings for material reducedin size within said chamber, means for introducing material into said chamber through the wall nearer said axis at a point adjacent the longitudinal center of said wall, and means for imparting to said chamber rapid oscillation of an arcuate extent materially'less than the angular extent of said arcuate chamber.

A18. An oscillating, elongated, size-reducing chamber having arcuate top and bottom walls of concentric curvature, said chamber of approximately uniform cross section at all 'points between its end portions on planes normal to said Walls and said chamber having an inlet in said top wall but spaced from the ends thereof for material to be processed and said chamber also having vorifices for the discharge, .while said chamber is in motion, of processed material in the bottom wall thereof and also in the top wall in the portions of the latter between said inlet and the ends of said top wall.

ROBERT S. BUTLER. 

